1. Field of the Invention
The present invention relates to a sales apparatus or vending machine, a sales method and a program, and more particularly to a sales apparatus or vending machine, a sales method and a program, suitable for use in selling electronic data.
2. Description of Related Art
In a communication system of related art including a transmitter, a communication medium and a receiver, communication has been established by providing a physical communication signal transmission path for transmitting a communication signal and another physical reference point path different from the communication signal transmission path for sharing a reference point for judging a high/low difference of the communication signal between the transmitter and receiver.
For example, Japanese Patent Application Publication Numbers H10-229357 and H11-509380 describe communication techniques using a human body as the communication medium. In both the documents, in addition to the use of a human body as a first communication path, direct electrostatic coupling between electrodes in the ground or space is used as a second communication path. The total communication path constituted of the first and second communication paths is structured to form a closed circuit.
In the communication system of this type, it is necessary to form, as a closed circuit, two communication paths of a communication signal transmission path and a reference point path (first and second communication paths) between the transmitter and receiver. However, since both the paths are different paths, these two paths are required to be established with stability. This may pose a fear of restrictions of communication usage environments.
For example, since an intensity of electrostatic coupling between the transmitter and a receiver on the reference point path depends on a distance between apparatus, reliability of the path changes with the distance. Namely, in this case, there is a fear that reliability of communication depends upon the distance between the transmitter and receiver. If there exist obstacles between the transmission and receiver, there is a fear that communication reliability may be changed.
Therefore, with the communication method of using two paths, a communication signal transmission path and a reference point path, as a closed circuit, usage environments greatly influence the communication reliability, so that it is difficult to realize stable communication.